Campervan Charging: DC-DC, Shore Power & Alternator Guide (2025)

· 4 min read

Your campervan charging system determines how quickly and reliably you can replenish the energy you use. Most systems use two or three charging sources working together: solar, alternator (DC-DC), and shore power.

This guide covers all three. For the complete system overview, see our campervan electrical system guide.

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The Three Charging Sources

1. DC-DC Charger (Alternator Charging)

A DC-DC charger takes power from your vehicle's starter battery (charged by the alternator) and uses it to charge your leisure battery. It's the most reliable charging source in the UK because it works regardless of weather — you charge every time you drive.

Why not a split charge relay? Modern vans (Euro 6, post-2015) have smart alternators that vary their output voltage. Split charge relays need a constant voltage to work. A DC-DC charger handles any input voltage. See DC-DC charger vs split charge relay for the full comparison.

Sizing: See 20A vs 30A vs 50A DC-DC charger. Most mid-range systems use 30A.

Top picks: See best DC-DC charger for campervans. The Victron Orion XS 30A is our top recommendation — see the install guide.

Charging speed: A 30A DC-DC charger adds about 360Wh per hour of driving. See how fast does a DC-DC charger charge for real-world data.

2. Shore Power (Hook-Up Charging)

Shore power lets you charge from a campsite mains hook-up (EHU). A dedicated 230V-to-12V charger converts mains power to the correct charging voltage for your leisure battery.

See shore power for campervans for the complete wiring and safety guide, and shore power inlet installation for the step-by-step process.

The Victron Blue Smart IP22 is the most popular shore power charger for campervans.

New to hook-ups? See EHU (electric hook-up) explained. Want to charge at home? See can I charge my campervan from my house.

3. Solar

Solar is covered in detail in our campervan solar setup guide. It's your primary charging source when parked up, but UK winters limit its output — which is why DC-DC charging is essential as a complement.

How All Three Work Together

All three sources can charge simultaneously without conflict. See how all three charging sources work together for the explanation of charging priority and current sharing.

The UK formula

For reliable year-round charging in the UK, you need at minimum: solar panels + DC-DC charger. Shore power is a nice backup but shouldn't be your primary strategy unless you're always at campsites.

Consumer Unit & RCD

If you have shore power or an inverter, UK regulations require a consumer unit with an RCD (Residual Current Device) and MCBs. See campervan consumer unit wiring for the full requirements including BS 7671 compliance.

Understanding Your Alternator

The type of alternator in your van affects which charging method you need. See Euro 5 vs Euro 6 alternators for how to identify yours.

FAQ

Do I need both solar and a DC-DC charger?

In the UK, yes — we strongly recommend both. Solar alone won't keep up in winter, and DC-DC alone means you need to drive every day. Together they provide reliable year-round charging.

Can I charge my campervan battery while driving?

Yes, that's exactly what a DC-DC charger does. It takes power from your alternator (via the starter battery) and charges your leisure battery. A 30A unit adds about 360Wh per hour of driving.

How long does it take to fully charge a campervan battery?

From a 30A DC-DC charger: a 200Ah battery from 20% to 100% takes about 5–6 hours of driving. From shore power with a 30A charger: about 6–8 hours. From solar: highly variable, 4–8 hours in summer, much longer in winter.